1. Technical Field
The invention relates to a switch technique of television channels. Particularly, the invention relates to an apparatus for switching television channels and a method thereof.
2. Related Art
Along with progress of multimedia technology, digital video devices such as digital televisions and set-top boxes are widely used. Multimedia practitioners also provide multiple television channels to facilitate the users enjoying rich audio and video resources.
When the user watches a digital television program of a certain channel, and wants to switch to an adjacent channel, it generally takes several seconds before images and sounds of the corresponding program are decoded after the user presses a corresponding key, which leads to a result that the user feels a noticeable pause. Such sense of pause is due to that a tuner in a digital television receiver is required to transmit a received video stream to an image decoding module for decoding, and the image decoding module performs video decoding according to a decoding technique corresponding to the video stream, and the above two steps consume more processing time. For example, the video stream is composed of an I-frame, a P-frame and a B-frame, and the image decoding module has to receive the I-frame in the video stream in order to decode the P-frame and the B-frame.
A channel switching time can be reduced in order to mitigate the aforementioned sense of pause, and one method thereof is to simultaneously use a plurality of tuners to reduce the time consumed in locking frequency points of the channels. However, based on statistics, it is known that the most time-consuming step is not switching of different frequency points, but is that the image decoding module cannot quickly decode the video stream. Therefore, it is necessary to provide a method to quickly switch television channels, such that the user may have better operation experience when watching the digital video device.